This html5rocks.com article on High DPI Canvas has been recomended on several places across SO. It describes how to use the backingStoreRatio value to correctly scale bitmaps on high DPI screens (retina etc). But I can not find any further reference to backingStoreRatio attribute in MDNs reference on CanvasRenderingContext2D nor with any other authority on the web.
Is this solution valid or deprecated? What is the recommended solution to drawing bitmaps to canvas on high res displays?